From: DL4YHF@aol.com
Message-ID: <50.f61cb99.277df99c@aol.com>
Date: Fri, 29 Dec 2000 09:28:44 EST
Subject: LF: Re: Ideas for a Slow CW-Viewer
To: rsgb_lf_group@blacksheep.org
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Hello Alberto and Group,

I have some ideas for a 'Slow-CW-Viewer' (some of them have been implemented 
in Spectrum Lab, others in Spectran, others not at all...)
How about this :

- adjustable 'color brightness' and 'contrast' with scrollbars for 
post-processing
- a 'time scroller' for the waterfall, optionally 'time labels' every (N) 
seconds
- a frequency and time grid for the waterfall
- a simple 'ASCII-export' feature similar to the ECLIPSE software
- a feature to ADD or SUBTRACT the audio frequency from the receiver's
  'zero beat' frequency so we could have a waterfall with 'absolute' frequency
  scale (for example, RX VFO set to 137.2kHz, audio frequency 507 Hz,
  display for the waterfall's marker = 137.707 kHz). 
The RX VFO frequency could be entered in an edit control or (if someone got 
enough time to implement it) could be read from the RX via serial interface.

An other point to think about is introducing a 'file format' to save spectral 
data. Such a file could contain FFT bins along with additional information, 
like :
  - date+time of the reception,
  - bandwith and resolution of the FFT bins, 
  - exact VFO frequency and LSB/USB information from time of reception
  - a few lines of plain text for comments, antenna description, location etc.
The file format (and/or the source code) should be published for all authors 
of FFT-DSP software. These files could be spread via the reflector and be 
loaded into the new 'viewer' for displaying, scrolling, zooming and other 
ways of post-processing). Though handling such a file wouldn't be as easy as 
sharing graphic 'waterfall' files, it offers flexibility for future analysis 
(beacon observation, signal/noise analysis, extraction of 'propagation data' 
etc).  Just an idea -- hw ?

By the way: The complete sourcecode of SpectrumLab is available at 
www.qsl.net/dl4yhf, if you want to take a look at them (written in C++).

73's and all the best for 2001 
    from Wolf, DL4YHF.